Welcome

AS61860 Assembler

ACKNOWLEDGMENT 


     Thanks  to  Edgar  Puehringer  for  his contribution of the
AS61860 cross assembler.  

        Edgar Peuhringer
        edgar_pue at yahoo dot com


61860 REGISTER SET 
     
The  SC61860  from  Sharp has 96 bytes of internal RAM which are
used as registers and hardware stack.  The last  four  bytes  of
the  internal  RAM  are  special  purpose registers (I/O, timers
...).  Here is a list of the 61860 registers:  

        Reg     Address         Common use
        ---     -------         ----------
        i, j    0, 1            Length of block operations
        a, b    2, 3            Accumulator       
        xl, xh  4, 5            Pointer for read operations
        yl, yh  6, 7            Pointer for write operations
        k - n   8 - 0x0b        General purpose (counters ...)
          -     0x0c - 0x5b     Stack
        ia      0x5c            Inport A
        ib      0x5d            Inport B
        fo      0x5e            Outport F
        cout    0x5f            Control port


     Other  parts  of  the  61860 are the 16 bit program counter
(pc) and 16 bit data pointer (dp).  The ALU has a carry flag (c)
and  a  zero  flag  (z).   There is an internal register d which
can't be accessed with machine instructions.  It is filled  from
i or j when executing block operations.  

     In  addition  there  are  three 7 bit registers p, q, and r
which are used to address the  internal  RAM  (r  is  the  stack
pointer, p and q are used for block operations).  

PROCESSOR SPECIFIC DIRECTIVES 

     The  AS61860 cross assembler has two (2) processor specific
assembler directives which are used for the etc mnemonic  (which
is a kind of a built-in switch/case statement):  

        .default        A 16 bit address (same as .dw)
        .case           One byte followed by a 16 bit address

Here is an example how this should be used (cut from a lst
file):

   022B 7A 05 02 18         614         PTC     0x05,   CONT16
   022F 69                  615         DTC
   0230 4C 01 25            616         .CASE   0x4C,   SLOADI
   0233 4D 01 2F            617         .CASE   0x4D,   SMERGI
   0236 51 01 D2            618         .CASE   0x51,   QUITI   
   0239 53 00 CD            619         .CASE   0x53,   LLISTI
   023C 56 01 D5            620         .CASE   0x56,   VERI
   023F 01 D1               621         .DEFAULT        CONT9

61860 INSTRUCTION SET 

     The following tables list all 61860 family mnemonics recog-
nized by the AS61860 assembler.  Most of the mnemonics are  con-
verted  into  8  bit  machine instructions with no argument or a
one- or two-byte argument.  There are some exceptions for this: 

        Mnemonic        Description
        --------        -----------
        jp              2 bit instruction, 6 bit argument
        cal             3 bit instruction, 13 bit argument
        ptc *)          1 byte instruction, 3 byte argument
        dtc *)          1 byte instruction, n bytes argument
 
        *) Not mentioned in the CPU specification from Sharp


Load Immediate Register 

        LII n           (n --> I)
        LIJ n
        LIA n
        LIB n
        LIP n
        LIQ n
        LIDP nm
        LIDL n          (DL is the low byte of DP)
        LP              (One byte version of LIP)
        RA              (Same as LIA 0, but only one byte)
        CLRA            (synonym for RA)


Load Accumulator 

        LDP             (P --> A)
        LDQ
        LDR
        LDM             ((P) --> A)
        LDD             ((DP) --> A)


Store Accumulator 

        STP             (A --> P)
        STQ
        STR
        STD             (A --> (DP))


Move Data 

        MVDM            ((P) --> (DP))
        MVMD            ((DP) --> (P))


Exchange Data 

        EXAB            (A <--> B)
        EXAM            (A <--> (P))


Stack Operations 

        PUSH            (R - 1 --> R, A --> (R))
        POP             ((R) --> A, R + 1 --> R)
        LEAVE           (0 --> (R))


Block Move Data 

        MVW             ((Q) --> (P), I+1 bytes)
        MVB             ((Q) --> (P), J+1 bytes)
        MVWD            ((DP) --> (P), I+1 bytes)
        MVBD            ((DP) --> (P), J+1 bytes)
        DATA            ((B,A) --> (P), I+1 bytes,
                        reads CPU ROM also)


Block Exchange Data 

        EXW             ((Q) <--> (P), I+1 bytes)
        EXB             ((Q) <--> (P), J+1 bytes)
        EXWD            ((DP) <--> (P), I+1 bytes)
        EXBD            ((DP) <--> (P), J+1 bytes)


Increment and Decrement 

        INCP            (P + 1 --> P)
        DECP
        INCI
        DECI
        INCJ
        DECJ
        INCA
        DECA
        INCB
        DECB
        INCK
        DECK
        INCL
        DECL
        IX              (X + 1 --> X, X --> DP)
        DX
        IY
        DY
        INCM *)
        DECM *)
        INCN *)
        DECN *)

        *) Not mentioned in the CPU specification from Sharp


Increment/Decrement with Load/Store 

        IXL             (Same as IX plus LDD)
        DXL
        IYS             (Same as IY plus STD)
        DYS


Fill 

        FILM            (A --> (P), I+1 bytes)
        FILD            (A --> (DP), I+1 bytes)


Addition and Subtraction 

        ADIA n          (A + n --> A)
        SBIA n
        ADIM n          ((P) + n --> (P))
        SBIM n
        ADM n           ((P) + A --> (P))
        SBM n
        ADCM n          ((P) + A --> (P), with carry)
        SBCM
        ADB             (like ADM, but 16 bit)
        SBB
        ADN             (like ADM, BCD addition, I+1 bytes)
        SBN
        ADW             ((P) + (Q) --> (P), BCD, I+1 bytes)
        SBW


Shift Operations 

        SRW             (shift I+1 bytes in (P) 4 bits right)
        SLW
        SR              (shift A 1 bit, with carry)
        SL
        SWP             (exchange low and high nibble of A)


Boolean Operations 

        ANIA n          (A & n --> A)
        ORIA n
        ANIM n          ((P) & n --> (P))
        ORIM n
        ANID n          ((DP) & n --> (DP))
        ORID n
        ANMA            ((P) & A --> (P))
        ORMA


Compare 

        CPIA n          (A - n --> c,z)
        CPIM n          ((P) - n --> c,z)
        CPMA            ((P) - A --> c,z)
        TSIA n          (A & n --> z)
        TSIM n          ((P) & n --> z)
        TSID n          ((DP) & n --> z)
        TSIP            ((P) & A --> z)


CPU Control 

        SC              (Set carry)
        RC
        NOPW            (no op)
        NOPT
        WAIT n          (wait 6+n cycles)
        WAITJ           (wait 5+4*I cycles)
        CUP             (synonym for WAITJ)


Absolute Jumps 

        JP nm
        JPZ nm          (on zero)
        JPNZ nm
        JPC nm
        JPNC nm
        PTC/DTC         (see 'Processor Specific Directives')
        PTJ/DTJ         (synonym for PTD/DTC)
        CPCAL/DTLRA     (synonym for PTC/DTC)
        CASE1/CASE2     (synonym for PTC/DTC)
        SETT/JST        (synonym for PTC/DTC)


Relative Jumps 

     These  operations  handle a jump relative to PC forward and
back with  a  maximum  distance  of  255  byte.   The  assembler
resolves 16 bit  addresses to 8 bit  relative  adresses.  If the
target address is to far away, an error will be generated.  Note
that relative jumps need 1 byte less than absolute jumps.  

        JRP nm
        JRZP nm
        JRNZP nm        (jump relative non zero plus direction)
        JRCP nm
        JRNCP nm
        JRM nm
        JRZM nm
        JRNZM nm
        JRCM nm         (jump relative on carry minus direction)
        JRNCM nm
        LOOP nm         (decrements (R) and makes a JRNCM)


Calls 

        CALL nm
        CAL nm          (nm must be <= 0x1fff,
                        1 byte less code than CALL)
        RTN


Input and output 

        INA             (IA --> A)
        INB
        OUTA
        OUTB
        OUTF            (A --> FO)
        OUTC            (control port)
        TEST n          (timers, pins & n --> z)


Unknown Commands 

        READ            ((PC+1) -> A)
        READM           ((PC+1) -> (P))
        WRIT            (???)

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Last Updated: April 2009